Sidelink resource indications and usage

ABSTRACT

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE. The UE may schedule, from among the candidate sidelink resources based at least in part on signal-to-interference ratios for the candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE. The UE may transmit, to the second UE, an indication of the candidate sidelink resources and the one or more scheduled sidelink resources. Numerous other aspects are described.

CROSS-REFERENCE TO RELATED APPLICATION

This Patent Application claims priority to U.S. Provisional Patent Application No. 63/200,946, filed on Apr. 5, 2021, entitled “SIDELINK RESOURCE INDICATIONS AND USAGE,” and assigned to the assignee hereof. The disclosure of the prior Application is considered part of and is incorporated by reference into this Patent Application.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for indicating and using sidelink resources.

BACKGROUND

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, orthogonal frequency-division multiple access (OFDMA) systems, single-carrier frequency-division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

A wireless network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs). A UE may communicate with a BS via the downlink and uplink. “Downlink” or “forward link” refers to the communication link from the BS to the UE, and “uplink” or “reverse link” refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a Node B, a gNB, an access point (AP), a radio head, a transmit receive point (TRP), a New Radio (NR) BS, or a 5G Node B.

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate on a municipal, national, regional, and even global level. NR, which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the 3GPP. NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE, NR, and other radio access technologies.

SUMMARY

In some aspects, a method of wireless communication performed by a first user equipment (UE) includes selecting one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE, and scheduling, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE. The method may include transmitting, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

In some aspects, a method of wireless communication performed by a first user UE includes receiving, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, and transmitting, to the second UE, a communication in one of the one or more candidate sidelink resources.

In some aspects, a first UE for wireless communication includes a memory and one or more processors, coupled to the memory, configured to select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE; schedule, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE; and transmit, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

In some aspects, a first UE for wireless communication includes a memory and one or more processors, coupled to the memory, configured to receive, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, and transmit, to the second UE, a communication in one of the one or more candidate sidelink resources.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a first UE, cause the first UE to select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE; schedule, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE; and transmit, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a first UE, cause the first UE to receive, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, and transmit, to the second UE, a communication in one of the one or more candidate sidelink resources.

In some aspects, a first apparatus for wireless communication includes means for selecting one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second apparatus to use for transmission to the first apparatus; means for scheduling, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first apparatus; and means for transmitting, to the second apparatus, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

In some aspects, a first apparatus for wireless communication includes means for receiving, from a second apparatus, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second apparatus and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, and means for transmitting, to the second apparatus, a communication in one of the one or more candidate sidelink resources.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the drawings and specification.

The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.

While aspects are described in the present disclosure by illustration to some examples, those skilled in the art will understand that such aspects may be implemented in many different arrangements and scenarios. Techniques described herein may be implemented using different platform types, devices, systems, shapes, sizes, and/or packaging arrangements. For example, some aspects may be implemented via integrated chip embodiments or other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, or artificial intelligence-enabled devices). Aspects may be implemented in chip-level components, modular components, non-modular components, non-chip-level components, device-level components, or system-level components. Devices incorporating described aspects and features may include additional components and features for implementation and practice of claimed and described aspects. For example, transmission and reception of wireless signals may include a number of components for analog and digital purposes (e.g., hardware components including antennas, radio frequency chains, power amplifiers, modulators, buffers, processors, interleavers, adders, or summers). It is intended that aspects described herein may be practiced in a wide variety of devices, components, systems, distributed arrangements, or end-user devices of varying size, shape, and constitution.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

FIG. 1 is a diagram illustrating an example of a wireless network, in accordance with the present disclosure.

FIG. 2 is a diagram illustrating an example of a base station in communication with a user equipment (UE) in a wireless network, in accordance with the present disclosure.

FIG. 3 is a diagram illustrating an example of sidelink communications, in accordance with the present disclosure.

FIG. 4 is a diagram illustrating an example of selecting sidelink resources, in accordance with the present disclosure.

FIG. 5 is a diagram illustrating an example of using a resource report for sidelink resources, in accordance with the present disclosure.

FIG. 6 is a diagram illustrating an example of indicating and using scheduled sidelink resources, in accordance with the present disclosure.

FIG. 7A is a diagram illustrating an example of indicating and using sidelink resources, in accordance with the present disclosure.

FIG. 7B is a diagram illustrating an example of resolving report conflicts, in accordance with the present disclosure.

FIG. 8 is a diagram illustrating examples of resources for requesting and reporting, in accordance with the present disclosure.

FIG. 9 is a diagram illustrating an example of indicating sidelink resources, in accordance with the present disclosure.

FIG. 10 is a diagram illustrating an example process performed, for example, by a first UE, in accordance with the present disclosure.

FIG. 11 is a diagram illustrating an example process performed, for example, by a first UE, in accordance with the present disclosure.

FIGS. 12-13 are block diagrams of example apparatuses for wireless communication, in accordance with the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, and/or the like (collectively referred to as “elements”). These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

It should be noted that while aspects may be described herein using terminology commonly associated with a 5G or NR radio access technology (RAT), aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G).

FIG. 1 is a diagram illustrating an example of a wireless network 100 in accordance with the present disclosure. The wireless network 100 may be or may include elements of a 5G (NR) network and/or an LTE network, among other examples. The wireless network 100 may include a number of base stations 110 (shown as BS 110 a, BS 110 b, BS 110 c, and BS 110 d) and other network entities. A base station (BS) is an entity that communicates with user equipment (UEs) and may also be referred to as an NR BS, a Node B, a gNB, a 5G node B (NB), an access point, or a transmit receive point (TRP). Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a BS and/or a BS subsystem serving this coverage area, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a closed subscriber group (CSG)). ABS for a macro cell may be referred to as a macro BS. ABS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in FIG. 1, a BS 110 a may be a macro BS for a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102 b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS may support one or multiple (e.g., three) cells. The terms “eNB”, “base station”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” may be used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some aspects, the BSs may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces such as a direct physical connection, or a virtual network using any suitable transport network.

Wireless network 100 may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of the data to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. In the example shown in FIG. 1, a relay BS 110 d may communicate with macro BS 110 a and a UE 120 d in order to facilitate communication between BS 110 a and UE 120 d. A relay BS may also be referred to as a relay station, a relay base station, or a relay.

Wireless network 100 may be a heterogeneous network that includes BSs of different types, such as macro BSs, pico BSs, femto BSs, and/or relay BSs. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have a high transmit power level (e.g., 5 to 40 watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 watts).

A network controller 130 may couple to a set of BSs and may provide coordination and control for these BSs. Network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with one another, directly or indirectly, via a wireless or wireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, and/or the like. A UE may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, and/or location tags that may communicate with a base station, another device (e.g., remote device), or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE). UE 120 may be included inside a housing that houses components of UE 120, such as processor components and/or memory components. In some aspects, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, and/or electrically coupled.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, and/or an air interface. A frequency may also be referred to as a carrier, and/or a frequency channel. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120 a and UE 120 e) may communicate directly using one or more sidelink channels (e.g., without using a base station 110 as an intermediary to communicate with one another). For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-pedestrian (V2P) protocol, or a vehicle-to-infrastructure (V2I) protocol), and/or a mesh network. In this case, the UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station 110.

In some aspects, UE 120 a may indicate available sidelink resources to UE 120 e, and the UE 120 e may select a sidelink resource for transmission from these available sidelink resources. The UE 120 e may also sense a sidelink channel to determine which sidelink resources are available. The UE 120 e may select a sidelink resource for transmission from the sidelink resources that UE 120 a indicates as available and/or from the sidelink resources that UE 120 e senses are available. As described in various aspects herein, the UE 102 a may schedule one or more preferred sidelink resources on behalf of the UE 102 e.

Devices of wireless network 100 may communicate using the electromagnetic spectrum, which may be subdivided based on frequency or wavelength into various classes, bands, channels, or the like. For example, devices of wireless network 100 may communicate using an operating band having a first frequency range (FR1), which may span from 410 MHz to 7.125 GHz, and/or may communicate using an operating band having a second frequency range (FR2), which may span from 24.25 GHz to 52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to as a “sub-6 GHz” band. Similarly, FR2 is often referred to as a “millimeter wave” band despite being different from the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. Thus, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like, if used herein, may broadly represent frequencies less than 6 GHz, frequencies within FR1, and/or mid-band frequencies (e.g., greater than 7.125 GHz). Similarly, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like, if used herein, may broadly represent frequencies within the EHF band, frequencies within FR2, and/or mid-band frequencies (e.g., less than 24.25 GHz). It is contemplated that the frequencies included in FR1 and FR2 may be modified, and techniques described herein are applicable to those modified frequency ranges.

As indicated above, FIG. 1 is provided as an example. Other examples may differ from what is described with regard to FIG. 1.

FIG. 2 is a diagram illustrating an example 200 of a base station 110 in communication with a UE 120 in a wireless network 100, in accordance with the present disclosure. Base station 110 may be equipped with T antennas 234 a through 234 t, and UE 120 may be equipped with R antennas 252 a through 252 r, where in general T≥1 and R≥1.

At base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS(s) selected for the UE, and provide data symbols for all UEs. Transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI)) and control information (e.g., CQI requests, grants, upper layer signaling) and provide overhead symbols and control symbols. Transmit processor 220 may also generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS), a demodulation reference signal (DMRS)) and synchronization signals (e.g., the primary synchronization signal (PSS) or a secondary synchronization signal (SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232 a through 232 t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232 a through 232 t may be transmitted via T antennas 234 a through 234 t, respectively.

At UE 120, antennas 252 a through 252 r may receive the downlink signals from base station 110 and/or other base stations and may provide received signals to demodulators (DEMODs) 254 a through 254 r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254 a through 254 r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller/processor 280. The term “controller/processor” may refer to one or more controllers, one or more processors, or a combination thereof. A channel processor may determine reference signal received power (RSRP) parameter, a received signal strength indicator (RSSI) parameter, a reference signal received quality (RSRQ) parameter, and/or a channel quality indicator (CQI) parameter, among other examples. In some aspects, one or more components of UE 120 may be included in a housing 284.

Network controller 130 may include communication unit 294, controller/processor 290, and memory 292. Network controller 130 may include, for example, one or more devices in a core network. Network controller 130 may communicate with base station 110 via communication unit 294.

Antennas (e.g., antennas 234 a through 234 t and/or antennas 252 a through 252 r) may include, or may be included within, one or more antenna panels, antenna groups, sets of antenna elements, and/or antenna arrays, among other examples. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include one or more antenna elements. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include a set of coplanar antenna elements and/or a set of non-coplanar antenna elements. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include antenna elements within a single housing and/or antenna elements within multiple housings. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include one or more antenna elements coupled to one or more transmission and/or reception components, such as one or more components of FIG. 2.

On the uplink, at UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports that include RSRP, RSSI, RSRQ, and/or CQI) from controller/processor 280. Transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254 a through 254 r (e.g., for DFT-s-OFDM, CP-OFDM), and transmitted to base station 110. In some aspects, a modulator and a demodulator (e.g., MOD/DEMOD 254) of the UE 120 may be included in a modem of the UE 120. In some aspects, the UE 120 includes a transceiver. The transceiver may include any combination of antenna(s) 252, modulators and/or demodulators 254, MIMO detector 256, receive processor 258, transmit processor 264, and/or TX MIMO processor 266. The transceiver may be used by a processor (e.g., controller/processor 280) and memory 282 to perform aspects of any of the methods described herein (for example, as described with reference to FIGS. 1-13).

At base station 110, the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller/processor 240. Base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244. Base station 110 may include a scheduler 246 to schedule UEs 120 for downlink and/or uplink communications. In some aspects, a modulator and a demodulator (e.g., MOD/DEMOD 232) of the base station 110 may be included in a modem of the base station 110. In some aspects, the base station 110 includes a transceiver. The transceiver may include any combination of antenna(s) 234, modulators and/or demodulators 232, MIMO detector 236, receive processor 238, transmit processor 220, and/or TX MIMO processor 230. The transceiver may be used by a processor (e.g., controller/processor 240) and memory 242 to perform aspects of any of the methods described herein (for example, as described with reference to FIGS. 1-13).

Controller/processor 280 of UE 120 and/or any other component(s) of FIG. 2 may perform one or more techniques associated with indicating and using sidelink resources, as described in more detail elsewhere herein. For example, controller/processor 280 of UE 120 and/or any other component(s) of FIG. 2 may perform or direct operations of, for example, process 1000 of FIG. 10, process 1100 of FIG. 11, and/or other processes as described herein. Memory 282 may store data and program codes for UE 120, respectively. In some aspects, memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, and/or interpreting) by one or more processors of the UE 120, may cause the one or more processors and/or the UE 120 to perform or direct operations of, for example, process 1000 of FIG. 10, process 1100 of FIG. 11, and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions, among other examples.

In some aspects, a first UE (e.g., UE 120) includes means for selecting one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE, means for scheduling, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE, and/or means for transmitting, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources. The means for the first UE to perform operations described herein may include, for example, one or more of antenna 252, demodulator 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, modulator 254, controller/processor 280, or memory 282.

In some aspects, the first UE includes means for receiving, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, and/or means for transmitting, to the second UE, a communication in one of the one or more candidate sidelink resources. The means for the first UE to perform operations described herein may include, for example, one or more of antenna 252, demodulator 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, modulator 254, controller/processor 280, or memory 282.

While blocks in FIG. 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, and/or the TX MIMO processor 266 may be performed by or under the control of controller/processor 280.

As indicated above, FIG. 2 is provided as an example. Other examples may differ from what is described with regard to FIG. 2.

FIG. 3 is a diagram illustrating an example 300 of sidelink communications, in accordance with the present disclosure.

As shown in FIG. 3, a first UE 302 may communicate with a second UE 304 (and one or more other UEs) via one or more sidelink channels 310. UE 302 and UE 304 may communicate using the one or more sidelink channels 310 for P2P communications, D2D communications, V2X communications (e.g., which may include V2V communications, V2I communications, and/or V2P communications) and/or mesh networking. In some aspects, UE 302 and UE 304 may correspond to one or more other UEs. In some aspects, the one or more sidelink channels 310 may use a PC5 interface and/or may operate in a high frequency band (e.g., the 5.9 gigahertz (GHz) band). Additionally, or alternatively, UE 302 and UE 304 may synchronize timing of transmission time intervals (TTIs) (e.g., frames, subframes, slots, or symbols) using global navigation satellite system (GNSS) timing.

As further shown in FIG. 3, the one or more sidelink channels 310 may include a physical sidelink control channel (PSCCH) 315, a physical sidelink shared channel (PSSCH) 320, and/or a physical sidelink feedback channel (PSFCH) 325. The PSCCH 315 may be used to communicate control information, similar to a physical downlink control channel (PDCCH) and/or a physical uplink control channel (PUCCH) used for cellular communications with a base station (e.g., base station 110) via an access link or an access channel. The PSSCH 320 may be used to communicate data, similar to a physical downlink shared channel (PDSCH) and/or a physical uplink shared channel (PUSCH) used for cellular communications with a base station via an access link or an access channel. For example, the PSCCH 315 may carry sidelink control information (SCI) 330, which may indicate various control information used for sidelink communications, such as one or more resources (e.g., time resources, frequency resources, and/or spatial resources) where a transport block (TB) 335 may be carried on the PSSCH 320. The TB 335 may include data. The PSFCH 325 may be used to communicate sidelink feedback 340, such as hybrid automatic repeat request (HARD) feedback (e.g., acknowledgement or negative acknowledgement (ACK/NACK) information), transmit power control (TPC), and/or a scheduling request (SR).

In some aspects, the one or more sidelink channels 310 may use resource pools. For example, a scheduling assignment (e.g., included in SCI 330) may be transmitted in sub-channels using specific resource blocks (RBs) across time. In some aspects, data transmissions (e.g., on the PSSCH 320) associated with a scheduling assignment may occupy adjacent RBs in the same subframe as the scheduling assignment (e.g., using frequency division multiplexing). In some aspects, a scheduling assignment and associated data transmissions are not transmitted on adjacent RBs.

In some aspects, UE 304 may operate using a transmission mode where resource selection and/or scheduling is performed by UE 302 (e.g., rather than a base station). In some aspects, UE 302 and/or UE 304 may perform resource selection and/or scheduling by sensing channel availability for transmissions. For example, UE 304 may measure an RSSI parameter (e.g., a sidelink-RSSI (S-RSSI) parameter) associated with various sidelink channels, may measure an RSRP parameter (e.g., a PSSCH-RSRP parameter) associated with various sidelink channels, may measure an RSRQ parameter (e.g., a PSSCH-RSRQ parameter) associated with various sidelink channels, and/or may determine a signal-to-interference ratio (SIR) associated with another UE on a sidelink channel. UE 304 may select a channel for transmission of a sidelink communication based at least in part on the measurement(s).

Additionally, or alternatively, UE 304 may perform resource selection and/or scheduling using SCI 330 received in the PSCCH 315, which may indicate occupied resources and/or channel parameters. Additionally, or alternatively, UE 304 may perform resource selection and/or scheduling by determining a channel busy rate (CBR) associated with various sidelink channels, which may be used for rate control (e.g., by indicating a maximum number of resource blocks that UE 304 can use for a particular set of subframes).

In the transmission mode where resource selection and/or scheduling is performed by UE 302, UE 302 may generate sidelink grants, and may transmit the grants in SCI 330. A sidelink grant may indicate, for example, one or more parameters (e.g., transmission parameters) to be used for an upcoming sidelink transmission, such as one or more resource blocks to be used for the upcoming sidelink transmission on the PSSCH 320 (e.g., for TBs 335), one or more subframes to be used for the upcoming sidelink transmission, and/or a modulation and coding scheme (MCS) to be used for the upcoming sidelink transmission. In some aspects, UE 302 may generate a sidelink grant that indicates one or more parameters for semi-persistent scheduling (SPS), such as a periodicity of a sidelink transmission. Additionally, or alternatively, UE 302 may generate a sidelink grant for event-driven scheduling, such as for an on-demand sidelink message.

UE 302 and UE 304 may operate in sidelink resource allocation Mode 2, in which UE 302 and UE 304 schedule or reserve their own sidelink resources without the assistance or direction of a base station (Mode 1). In some aspects, UE 302 may indicate available sidelink resources to UE 304, and UE 304 may select a sidelink resource for transmission from these available sidelink resources. UE 304 may also sense one or more of the sidelink channels 310 to determine which sidelink resources are available. UE 304 may select a sidelink resource for transmission from the sidelink resources that UE 302 indicates as available and/or from the sidelink resources that UE 304 senses are available. As described in various aspects herein, UE 302 may schedule one or more preferred sidelink resources on behalf of UE 304.

As indicated above, FIG. 3 is provided as an example. Other examples may differ from what is described with regard to FIG. 3.

FIG. 4 is a diagram illustrating an example 400 of selecting sidelink resources, in accordance with the present disclosure. Example 400 shows a UE 402 (e.g., a UE 302) that may receive communications on a sidelink channel from other UEs (e.g., a UE 304), such as UE 404, UE 406, and/or UE 408.

As described in connection with FIGS. 4-9, UE 404 is a transmitting UE that is transmitting communications to UE 402, which is a receiving UE. UE 404 may use a report from UE 402, which may act as a reporting UE that reports available sidelink resources. Example 400 shows an availability report from UE 402 to UE 404 and a communication from UE 404 to UE 402.

If UE 404 is to transmit a communication to UE 402, UE 404 may sense the sidelink channel in a sensing window to determine which sidelink resources (e.g., subcarriers, subchannels) are available. A sidelink resource may be considered available if the sidelink resource was clear or had a signal energy (e.g., RSRP) that satisfied an availability threshold (e.g., measured interference or energy on the channel is lower than a maximum decibel-milliwatts (dBm) or dB, RSRP threshold). The availability threshold may be configured per transmission priority and receive priority pair. UE 404 may measure DMRSs on a PSCCH or a PSSCH, according to a configuration.

For example, UE 404 may prepare to transmit a communication to UE 402. UE 404 may have already sensed previous sidelink resources and successfully decoded SCI from UE 406 and UE 408. UE 404 may try to reserve sidelink resources, and thus may check the availability of the future sidelink resources reserved by UE 406 and UE 408 by sensing the sidelink channel in the sensing window. UE 404 may measure an RSRP of a signal from UE 408 in sidelink resource 410, and an RSRP of a signal from UE 406 in sidelink resource 412. If an observed RSRP satisfies the RSRP threshold (e.g., is lower than a maximum RSRP), the corresponding sidelink resource may be available for reservations by UE 404. UE 404 may reserve the sidelink resource (which may be a random selection from available resources). For example, UE 404 may select and reserve sidelink resource 414 for transmission. This may be in a time slot after which UE 406 and UE 408 had used sidelink resources, and UE 404 may have sensed these sidelink resources earlier.

There may be a resource selection trigger to trigger selection of sidelink resources after a processing time T_(proc, 0), and before another processing time T_(proc, 1) before a resource selection window from which sidelink resources are available. The resource selection window may be a time window from which sidelink resources may be selected, and the resource selection window may extend for a remaining packet delay budget (PDB).

UE 404 may be power-sensitive and thus may not afford to continually sense all of the sidelink resources. UE 402 may be more capable of sensing and reporting on the sidelink resources because, for example, UE 402 may be a smart phone while UE 404 may be a smart watch. UE 402 may receive unicast communications from UE 404, and UE 402 may report back available resources to UE 404. UE 402 may continually sense the sidelink resources and measure interference levels involving neighboring UEs. For example, UE 402 may measure an RSRP of a signal from neighboring UE 406 as −92 dBm and an RSRP of a signal from neighboring UE 408 as −102 dBm. For a signal of a last transmission of UE 404, UE 402 measured a target signal level with an RSRP that was −90 dBm. UE 402 may estimate an SIR of a signal between UE 402 and UE 404 as −90−(−92)=2 dB and an SIR between UE 404 and UE 408 as −90−(−102)=12 dB. If the SIR of a signal from UE 404 to UE 402 with interference from UE 408 is large enough (satisfies an availability threshold) for reliable communication between UE 402 and UE 404, UE 402 may mark a sidelink resource that was reserved by UE 408 as available for use for a communication from UE 404 to UE 402. This may be useful when UE 404 has more than one data stream with varying Quality of Service (QoS) requirements or transmissions with different MCS indices.

As indicated above, FIG. 4 is provided as an example. Other examples may differ from what is described with regard to FIG. 4.

FIG. 5 is a diagram illustrating an example 500 of using a resource report for sidelink resources, in accordance with the present disclosure. Example 500 shows that UE 402 may transmit a report to UE 404.

UE 402 may transmit a report 502 indicating an availability of each sidelink resource. Rows in the report 502 may represent subcarriers or subchannels, and columns may represent time units (e.g., slots, symbols). The report 502 may be a binary report, such as a bitmap. For example, UE 402 may report a 1 bit for available and a 0 bit for unavailable. UE 404 may decode the report 502 and select (e.g., randomly) N resources from the available sidelink resources for potential N transmissions of a newly generated packet, or a packet of a transport block that has not been transmitted before. As shown by selection 504, UE 404 may select N=4 sidelink resources from the available sidelink resources indicated by the report 502.

As indicated above, FIG. 5 is provided as an example. Other examples may differ from what is described with regard to FIG. 5.

FIG. 6 is a diagram illustrating an example 600 of indicating and using scheduled sidelink resources, in accordance with the present disclosure.

UE 402 may prefer that UE 404 use sidelink resources with lower expected interference levels over other sidelink resources. If so, according to various aspects described herein, UE 402 may schedule one or more sidelink resources on behalf of UE 404 when indicating available sidelink resources to UE 404. UE 402 may still allow UE 404 to select other sidelink resources from the remaining available sidelink resources. By scheduling preferred sidelink resources for UE 404 that are available, UE 402 may cause UE 404 to conserve power, processing resources, and signaling resources because UE 404 performs less sensing and scheduling of sidelink resources. UE 404 may still have flexibility to sense the sidelink channel and select sidelink resources to avoid interference or collisions that degrade communications, which conserves power, processing resources, and signaling resources that would otherwise be wasted on failed transmissions and retransmissions.

For example, UE 404 may be configured to make a maximum of N transmissions for a packet or for a transport block. UE 402 may sense the channel and select a set of candidate sidelink resources in the resource selection window of UE 404 for the N transmissions. Within the set of candidate sidelink resources, UE 402 may select and schedule M scheduled sidelink resources, where M may be 0 or up to N of the candidate sidelink resources (0≤M≤N) of UE 404. Example 600 shows a report 602 from UE 402 indicating the set of candidate sidelink resources (resources marked with a “1”). The report 602 also indicates a scheduled sidelink resource (resource marked with “S”) that UE 402 has scheduled for UE 404 based at least in part on sensing the sidelink channel and detecting lower interference for the scheduled sidelink resource.

In some aspects, if M is less than N, UE 404 may select other sidelink resources from the set of candidate sidelink resources for any remaining transmissions up to N (N−M sidelink resources for N−M transmissions). As shown by selection 604, UE 404 may select the scheduled sidelink resource 606 for a first transmission and select another candidate sidelink resource 608 for a second transmission. If M=0, then report 602 may be similar to a report that is regularly transmitted.

In some aspects, UE 404 may sense the channel, and based at least in part on sensing the sidelink channel and measuring interference from the location of UE 404, may not use the scheduled candidate sidelink resource indicated in the report 602. Rather, UE 404 may select another candidate sidelink resource indicated as available in the report 602.

In some aspects, if M=N, UE 402 may indicate N scheduled sidelink resources by listing the respective indices of the N scheduled sidelink resources in the corresponding resource selection window of UE 404. UE 402 may send availability information in addition to the indices of the N scheduled sidelink resources. The additional availability information may include an indication of available candidate sidelink resources, which gives UE 404 flexibility to alter some selections from any scheduled sidelink resources indicated by UE 402. For example, if UE 404 senses the sidelink channel partially or fully, UE 404 may combine its own sensing results with the additional availability information from UE 402, in order to have a better picture of sidelink channel availability.

UE 404 may use the report 602 for an initial transmission of a transport block. For example, UE 404 may have received an indication of M=1 scheduled sidelink resource in the report 602 for an initial transmission of a transport block and a set of candidate sidelink resources in the form of a resource availability list or bitmap, as shown in FIG. 6. Then, UE 404 may make its initial transmission on the scheduled sidelink resource and have freedom to select from among the remaining candidate sidelink resources that are indicated as available in the report 602 from UE 402 to make remaining N−1 re-transmissions if needed. By using the scheduled sidelink resource indicated in the report 602 for the initial transmission for the transport block, the UE 404 may have a better chance of avoiding interference or a collision with the initial transmission, which may occur without prior knowledge of a preferred sidelink resource.

As indicated above, FIG. 6 is provided as an example. Other examples may differ from what is described with regard to FIG. 6.

FIG. 7A is a diagram illustrating an example 700 of indicating and using sidelink resources, in accordance with the present disclosure. Example 700 shows that UE 402, UE 404, and UE 406 may communicate with each other via one or more sidelink communications. In some aspects, UE 402, UE 404, and/or UE 406 may communicate (e.g., transmit an uplink transmission and/or receive a downlink transmission) with a base station. UE 402, UE 404, UE 406, and any base station may be part of a wireless network (e.g., wireless network 100). As described in connection with FIGS. 4-6, UE 404 is the reporting UE, and UE 402 is the UE transmitting a communication.

As shown by reference number 705, UE 402 may sense a sidelink channel in a sensing window for UE 404 (e.g., using antenna 252, demodulator 254, MIMO detector 256, receive processor 258, controller/processor 280, and/or memory 282). UE 402 may sense the sidelink channel based at least in part on past sidelink resources used by UE 404 or other UEs and/or future reserved sidelink resources for UE 404 or other UEs. As shown by reference number 710, UE 402 may select candidate sidelink resources that are clear or at least satisfy an availability threshold (e.g., minimum SIR) and generate an indication (e.g., report, list, bitmap) of the candidate sidelink resources (e.g., using controller/processor 280 or memory 282). UE 402 may also select one or more preferred sidelink resources for UE 404 and schedule the one or more of the preferred sidelink resources for UE 404. UE 402 may mark the scheduled sidelink resources in the indication.

As shown by reference number 715, UE 402 may transmit the indication via a radio resource control (RRC) message, a medium access control control element (MAC-CE), and/or downlink control information (DCI) (e.g., using antenna 252, transmit processor 264, TX MIMO processor 266, modulator 254, controller/processor 280, and/or memory 282). In some aspects, as shown by reference number 720, UE 404 may receive an indication of reserved and/or available sidelink resources from another reporting UE, such as UE 406 (e.g., using antenna 252, demodulator 254, MIMO detector 256, receive processor 258, controller/processor 280, and/or memory 282). The indications from UE 402 and UE 406 may be in unicast transmissions to UE 404.

As shown by reference number 725, UE 404 may (optionally) sense the sidelink channel for scheduled sidelink resources indicated by UE 402, other candidate sidelink resources indicated by UE 402, reserved sidelink resources indicated by UE 406, and/or any available sidelink resources indicated by UE 406 (e.g., using antenna 252, demodulator 254, MIMO detector 256, receive processor 258, controller/processor 280, and/or memory 282). As shown by reference number 730, UE 404 may select sidelink resources from available sidelink resources indicated by UE 402 (e.g., using controller/processor 280 and/or memory 282). UE 404 may use a scheduled sidelink resource indicated by UE 402. For any remaining transmissions, UE 404 may select other candidate sidelink resources indicated by UE 402. UE 404 may take into account any reserved sidelink resources or available sidelink resources indicated by UE 406. As shown by reference number 735, UE 404 may transmit a communication to UE 402 on a selected sidelink resource (e.g., using antenna 252, transmit processor 264, TX MIMO processor 266, modulator 254, controller/processor 280, and/or memory 282). UE 404 may transmit other communications to UE 402 with other selected sidelink resources.

In some aspects, availability information from UE 406 may conflict with availability information from UE 402, and conflicted sidelink resources may include the scheduled sidelink resources and/or other candidate sidelink resources indicated by UE 402. For example, UE 402 may indicate that a sidelink resource on the sidelink channel is available as a candidate sidelink resource, but UE 406 may indicate that the sidelink resource is not available. The sidelink resource may have interference or may be reserved. That is, some conflicts may exist for sidelink resources that are not disjoint in a time-frequency grid of a resource pool.

In some aspects, UE 404 may deduce the availability of sidelink resources by combining availability information (e.g., binary reports) from multiple UEs. For example, UE 404 may perform a resource-wise AND operation such that a sidelink resource is considered available if it is indicated as available by both UE 402 and UE 406. For a sidelink resource with differing availability per UE (resource conflict), UE 404 has two options. In one option, UE 404 may consider a scheduled sidelink resource indicated by UE 402 as unavailable in order to protect the scheduled sidelink resource from a possible collision due to a missed reservation by UE 402. UE 404 may not transmit a communication in the scheduled sidelink resource. In a second option, UE 404 may consider the scheduled sidelink resource as available and proceed with transmitting a communication in the scheduled sidelink resource based at least in part on sensing results rendering an interference level that satisfies the availability threshold, locations of UE 402 and/or UE 406 with respect to UE 404, and/or a network layout of UE 402 and/or UE 406 with respect to UE 404. That is, UE 404 may use information about the UE locations and the network layout to determine that the scheduled sidelink resource will not be interfered with and may use the scheduled sidelink resource.

In some aspects, if there is a conflict with scheduled sidelink resources and/or candidate sidelink resources, UE 404 may resolve a conflict and/or prioritize the scheduling sidelink resources of different UEs in various ways. For example, UE 404 may compare priorities of packets destined for each destination UE and use the sidelink resource scheduled by the UE whose packet has the highest priority. UE 404 may compare remaining PDBs of corresponding packets for each UE destination and use the scheduled sidelink resource for the packet with the shortest remaining PDB.

In some aspects, UE 404 may select a sidelink resource based at least in part on an application of a fairness rule between the UEs. For example, UE 404 may alternate between reporting UEs to select a different UE's scheduled sidelink resource at a given time (e.g., round-robin selection). UE 404 may compare a buffer status corresponding to each flow destined to the reporting UEs. For example, UE 404 may prefer using the sidelink resource for the longest queue.

In some aspects, UE 404 may use sidelink channel state information (SL-CSI) report values from conflicting reporting UEs. For example, UE 404 may prioritize a sidelink resource with a weaker link. UE 404 may select a sidelink resource based at least in part on a path loss, distance estimations between UE 404 and other reporting UEs (e.g., UE 402, UE 406, UE 408), and/or zone identifiers (IDs) for the reporting UEs. For example, UE 404 may prioritize using a sidelink resource having a higher path loss and/or a greater distance.

In some aspects, UE 404 may consider reliability requirements on each link to the reporting UEs. For example, UE 404 may select a sidelink resource of a link with a higher reliability than other links. UE 404 may consider power control levels used on each link. For example, UE 404 may select a sidelink resource of a link with a lower power level for a conflicted sidelink resource. UE 404 may consider a utilization state of a feedback message, such as a HARQ-ACK on flows to the reporting UEs. For example, UE 404 may select a sidelink resource of a flow that uses blind transmissions (non-HARQ-ACK). UE 404 may consider communication range requirements on each link. For example, UE 404 may select a sidelink resource having a longer range requirement than range requirements of other sidelink resources. UE 404 may consider a cast type (e.g., unicast, groupcast, broadcast) of communications for each flow. For example, UE 404 may prioritize sidelink resources associated with one of the cast types. In other words, UE 404 may have various options for resolving sidelink resource conflicts between UEs.

FIG. 7B is a diagram illustrating an example of resolving report conflicts, in accordance with the present disclosure. In some scenarios, as shown by reference number 740, there may be multiple sidelink resource reports (e.g., availability and/or scheduled) from multiple UEs (e.g., UE 402, UE 406, UE 408). Availability reports and/or scheduled reports may be combined. For example, multiple availability reports may be combined via an AND operation of available sidelink resources in the reports. That is, sidelink resources that are available will be indicated as available in each of the reports, and the AND operation is used to identify the available sidelink resources that overlap among the reports (available throughout every report). If a report is removed from consideration, the removed report will not be part of the combining (e.g., AND operation).

The combining of multiple reports may not achieve the availability threshold (e.g., minimum percentage of sidelink resource availability for using the available sidelink resources). In some aspects, rather than combining all of the availability reports, UE 404 may combine reports per group of UEs, as shown by reference number 745. For example, when UE 404 receives more than one report from members of a groupcast or broadcast session, UE 404 may combine reports only from UEs that are within a group. This may mean that separate output results are utilized for different groups. A given reporting UE may belong to more than one group. For reports received for a unicast session, UE 404 may directly use the reports individually, or combine any reports originating from nearby UEs based on zone identifiers (IDs) or locations (if known) of the nearby UEs. However, if the availability threshold is not satisfied in a given group, UE 404 may pursue another option.

In some aspects, as shown by reference number 750, UE 404 may combine reports that belong to UEs in a cluster, which may be a geographical area, such as area 752. The UEs in the cluster may be closely located to each other. UE 404 may use one specific AND-combined report per cluster if a UE from that cluster is an intended receiver. If the availability threshold (e.g., X % resource availability) cannot be satisfied in a given cluster, UE 404 may pursue other options.

In some aspects, if the availability threshold is not satisfied (e.g., the availability percentage is less than the availability percentage defined as the availability threshold), UE 404 may postpone sidelink resource selection for one of the transmissions. UE 404 may omit the corresponding report(s) received from the target UE 402 and recombine the remaining reports as described with respect to reference number 745 or reference number 750. In other words, when combining reports, UE 404 may remove the report of the intended target (e.g., UE 402) from consideration to satisfy the availability threshold. In this way, UE 404 may proceed with transmission to UE 402 while taking a chance that there may be a conflict. It may be that the transmission is a high priority transmission and thus the transmission may proceed in any event (and be retransmitted if necessary). UE 404 may iteratively follow the same approach with other reports until the availability threshold is satisfied. The rule for selecting the postponed transmission at any time may be based at least in part on parameters described above in connection with FIG. 7A.

In some aspects, if the availability threshold is not satisfied, as shown by reference number 755, UE 404 may postpone sidelink resource selection for a group of transmissions, transmissions for a cluster of UEs, or for all transmissions. UE 404 may postpone transmissions for a given number of slots and recheck the report combining at a corresponding slot with new reports that are received during this time.

In some aspects, if a sidelink resource scheduled by a scheduled report is not available according to an availability report, as shown by reference number 760, UE 404 may avoid a sidelink resource scheduled by UE 402 since the sidelink resource is indicated as unavailable according to at least one other UE. Then, UE 404 may select a sidelink resource from available sidelink resources indicated in an availability report from UE 402, after combining the availability report with availability reports of other UEs. UE 404 may combine the availability reports by group or per cluster. UE 404 may mark the avoided sidelink resource as unavailable in other reports.

In some aspects, if a sidelink resource scheduled by a scheduled report is not available according to an availability report, as shown by reference number 765, UE 404 may still use the scheduled sidelink resource. UE 404 may have the location information (e.g., the zone IDs or location coordinates) of UE 402, UE 406, and/or UE 408. If the distance between UEs, such as between UE 402 and UE 406, is smaller than a pre-configured threshold, UE 404 may avoid the scheduled resource.

UE 404 may select a sidelink resource based at least in part on the parameters described above in connection with FIG. 7A. A parameter may satisfy a parameter threshold that is specific to the parameter. For example, if the sidelink resource scheduled by UE 402 corresponds to a packet with a priority level higher than a pre-configured priority threshold, then UE 404 may use the scheduled sidelink resource.

In some aspects, if a scheduled sidelink resource conflicts with another scheduled sidelink resource, UE 404 may select the scheduled resource to be used with UE 402 and select other sidelink resources for other UEs after combining availability reports of the other UEs. The scheduled sidelink resource that is selected may be marked as unavailable in other availability reports. When the conflicting scheduled sidelink resources are received from members of the same groupcast or broadcast sessions, UE 404 may select one of the conflicting scheduled sidelink resources randomly. By following such rules for conflicting sidelink resource reports, UE 404 may improve throughput and reduce latency while attempting to reduce conflicts. As a result, UE 404 and other UEs conserve processing resources and signaling resources.

As indicated above, FIG. 7A and FIG. 7B are provided as examples. Other examples may differ from what is described with regard to FIG. 7A and FIG. 7B.

FIG. 8 is a diagram illustrating examples 800 and 802 of resources for requesting and reporting, in accordance with the present disclosure.

A UE may be configured to use certain resources for requesting resources and/or for reporting. Example 800 shows resources for requesting transmissions and/or reports. The resources for requesting are configured with a certain periodicity. The resources for reporting may also have a periodicity. Example 800 shows the resources for requesting in one sidelink slot, while example 802 shows the resources for reporting that are distributed over multiple sidelink slots. Each request resource may be in a single subchannel or in multiple subchannels.

As indicated above, FIG. 8 provides some examples. Other examples may differ from what is described with regard to FIG. 8.

FIG. 9 is a diagram illustrating an example 900 of indicating sidelink resources, in accordance with the present disclosure. Example 900 shows time and frequency sidelink resources (e.g., frequency subchannels and time slots) that may be marked as scheduled. A reporting period may be 8 slots.

UE 402 may have information of a periodic pattern for arrival of new packets with respect to UE 404. For example, a new packet of a transport block may arrive in slot 3 (as a resource selection trigger). UE 402 may also have information that UE 404 is going to use a Report 0 from UE 402 at slot 0 for an initial resource selection for the transport block. Accordingly, UE 402 may mark a subset of resources in Report 0, but not in Report 1 or Report 2. Therefore, there may be no scheduled resources indicated in Report 1 or Report 2, because only Report 0 applies to slot 3. UE 404 may then make 4 sidelink resource selections based at least in part on the Report 0 received in slot 0. In other words, UE 402 may use periodicity information for UE 404 to mark candidate sidelink resources and/or scheduled sidelink resources. If traffic at UE 404 is periodic, then the reporting of UE 402 may also be periodic. In this scenario, UE 402 may schedule (mark) resources only when UE 402 expects that UE 404 is going to use the scheduled resources for a newly generated packet. Therefore, the scheduling of resources may be selective and apply to only a subset of reports in time. This conserves signaling resources.

If traffic at UE 404 is aperiodic, UE 404 may request a sidelink resource availability report from UE 402. UE 402 may use requests from UE 404 as triggering events to schedule sidelink resources for UE 404. When there is no request, UE 402 may still generate a report due to some other triggering event (e.g., mobility operations, change in UE status, traffic conditions) and may leave some candidate sidelink resources unscheduled (unmarked) so that UE 404 may select other candidate sidelink resources if there is a need (e.g., for retransmissions).

As indicated above, FIG. 9 is provided as an example. Other examples may differ from what is described with regard to FIG. 9.

FIG. 10 is a diagram illustrating an example process 1000 performed, for example, by a first UE, in accordance with the present disclosure. Example process 1000 is an example where the UE (e.g., UE 120, UE 402) performs operations associated with sidelink resource indications and usage.

In FIG. 10, UE 402 may be referred to as a “first UE” and UE 404 may be referred to as a “second UE” when discussing operations from the viewpoint of UE 402. In FIG. 11, UE 404 may be referred to as the “first UE” and UE 402 may be referred to as the “second UE” when discussing operations from the viewpoint of UE 404.

As shown in FIG. 10, in some aspects, process 1000 may include selecting one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE (block 1010). For example, the UE (e.g., using selection component 1208 depicted in FIG. 12) may select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE, as described above (e.g., operation 710 depicted in FIG. 7).

As further shown in FIG. 10, in some aspects, process 1000 may include scheduling, from among the one or more candidate sidelink resources based at least in part on SIRs for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE (block 1020). For example, the UE (e.g., using scheduling component 1210 depicted in FIG. 12) may schedule, from among the one or more candidate sidelink resources based at least in part on SIRs for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE, as described above (e.g., operation 710 depicted in FIG. 7).

As further shown in FIG. 10, in some aspects, process 1000 may include transmitting, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources (block 1030). For example, the UE (e.g., using transmission component 1204 depicted in FIG. 12) may transmit, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources, as described above (e.g., operation 715 depicted in FIG. 7).

Process 1000 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, process 1000 includes receiving a communication from the second UE on one of the one or more scheduled sidelink resources. In a second aspect, alone or in combination with the first aspect, the communication is an initial transmission of a transport block from the second UE.

In a third aspect, alone or in combination with one or more of the first and second aspects, process 1000 includes receiving a communication from the second UE on one of the one or more candidate sidelink resources that is not one of the one or more scheduled sidelink resources.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the indication includes a bitmap for the one or more candidate sidelink resources, and the one or more scheduled sidelink resources are marked in the indication. In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the indication is transmitted according to a periodic pattern. In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the indication is transmitted for a generated packet that has not been transmitted.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the indication is transmitted based at least in part on a request from the second UE or a triggering event.

Although FIG. 10 shows example blocks of process 1000, in some aspects, process 1000 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in FIG. 10. Additionally, or alternatively, two or more of the blocks of process 1000 may be performed in parallel.

FIG. 11 is a diagram illustrating an example process 1100 performed, for example, by a first UE, in accordance with the present disclosure. Example process 1100 is an example where the UE (e.g., UE 120, UE 404) performs operations associated with sidelink resource indications and usage. The first UE of FIG. 11 (e.g., UE 404) may be the second UE described in connection with FIG. 10.

As shown in FIG. 11, in some aspects, process 1100 may include receiving, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources (block 1110). For example, the UE (e.g., using reception component 1302 depicted in FIG. 13) may receive, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, as described above (e.g., operation 715 depicted in FIG. 7).

As further shown in FIG. 11, in some aspects, process 1100 may include transmitting, to the second UE, a communication in one of the one or more candidate sidelink resources (block 1120). For example, the UE (e.g., using transmission component 1304 depicted in FIG. 13) may transmit, to the second UE, a communication in one of the one or more candidate sidelink resources, as described above (e.g., operation 735 depicted in FIG. 7).

Process 1100 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, transmitting the communication includes transmitting the communication to the second UE in one of the one or more scheduled sidelink resources. In a second aspect, alone or in combination with the first aspect, the communication is an initial transmission of a transport block to the second UE.

In a third aspect, alone or in combination with one or more of the first and second aspects, process 1100 includes sensing the sidelink channel, and transmitting the communication includes transmitting the communication to the second UE in one of the one or more candidate sidelink resources that is not among the one or more scheduled sidelink resources, based at least in part on the sensing of the sidelink channel.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the indication includes a bitmap for the one or more candidate sidelink resources, and the one or more scheduled sidelink resources are marked in the indication as scheduled. In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the communication is a generated packet that has not been transmitted.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, process 1100 includes transmitting a request for the one or more candidate sidelink resources.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, process 1100 includes selecting the one of the one or more candidate sidelink resources based at least in part on sidelink resource information from a third UE. In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources indicated by the second UE, and process 1100 includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the third UE.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process 1100 includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of a packet priority or a remaining PDB.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process 1100 includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of an application of a fairness rule to the second UE and the third UE or a buffer status corresponding to flows from the first UE to the second UE and the third UE.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process 1100 includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of sidelink channel state information reports for the second UE and the third UE, pathloss information for the second UE and the third UE, distance estimations for the second UE and the third UE, or zone identifiers for the second UE and the third UE.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process 1100 includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on, for links to the second UE and the third UE, one or more of reliability requirements, power control levels, feedback message utilization states, communication range requirements, or communication cast types.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process 1100 includes considering a conflicted scheduled sidelink resource as unavailable for transmission and transmitting the communication on another scheduled sidelink resource or candidate sidelink resource indicated by the second UE.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process 1100 includes considering a conflicted candidate sidelink resource or a conflicted scheduled sidelink resource as available for transmission and proceeding with transmitting the communication on the conflicted scheduled sidelink resource, based at least in part on one or more of a location of the third UE with respect to one or more of the first UE or the second UE, a network layout of the third UE with respect to one or more of the first UE or the second UE, or a sensing result for the conflicted scheduled sidelink resource satisfying an interference threshold.

In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and process 1100 includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs per group of UEs.

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and process 1100 includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs per geographical cluster of UEs.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and process 1100 includes postponing selection of the one of the one or more candidate sidelink resources for transmission.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and process 1100 includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs, without consideration of the one or more candidate sidelink resources indicated by the second UE.

In an eighteenth aspect, alone or in combination with one or more of the first through seventeenth aspects, process 1100 includes iteratively removing sidelink resource information for individual UEs of the other UEs from consideration until an availability threshold is satisfied.

In a nineteenth aspect, alone or in combination with one or more of the first through eighteenth aspects, the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with one of the one or more scheduled sidelink resources indicated by the second UE, and process 1100 includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs based at least in part on a specified parameter for the first UE satisfying a parameter threshold.

In a twentieth aspect, alone or in combination with one or more of the first through nineteenth aspects, the sidelink resource information from one or more other UEs includes one or more scheduled sidelink resources that conflict with one of the one or more scheduled sidelink resources indicated by the second UE, and process 1100 includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by candidate sidelink resources in the sidelink resource information from the one or more other UEs.

Although FIG. 11 shows example blocks of process 1100, in some aspects, process 1100 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in FIG. 11. Additionally, or alternatively, two or more of the blocks of process 1100 may be performed in parallel.

FIG. 12 is a block diagram of an example apparatus 1200 for wireless communication. The apparatus 1200 may be a first UE, or a first UE may include the apparatus 1200. In some aspects, the apparatus 1200 includes a reception component 1202 and a transmission component 1204, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus 1200 may communicate with another apparatus 1206 (such as a UE, a base station, or another wireless communication device) using the reception component 1202 and the transmission component 1204. As further shown, the apparatus 1200 may include one or more of a selection component 1208 and/or a scheduling component 1210, among other examples.

In some aspects, the apparatus 1200 may be configured to perform one or more operations described herein in connection with FIGS. 1-9. Additionally, or alternatively, the apparatus 1200 may be configured to perform one or more processes described herein, such as process 1000 of FIG. 10. In some aspects, the apparatus 1200 and/or one or more components shown in FIG. 12 may include one or more components of the UE described above in connection with FIG. 2. Additionally, or alternatively, one or more components shown in FIG. 12 may be implemented within one or more components described above in connection with FIG. 2. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component 1202 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 1206. The reception component 1202 may provide received communications to one or more other components of the apparatus 1200. In some aspects, the reception component 1202 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components of the apparatus 1200. In some aspects, the reception component 1202 may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with FIG. 2.

The transmission component 1204 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 1206. In some aspects, one or more other components of the apparatus 1200 may generate communications and may provide the generated communications to the transmission component 1204 for transmission to the apparatus 1206. In some aspects, the transmission component 1204 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus 1206. In some aspects, the transmission component 1204 may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with FIG. 2. In some aspects, the transmission component 1204 may be co-located with the reception component 1202 in a transceiver.

The selection component 1208 may select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE (apparatus 1200). The reception component 1202 may sense the sidelink channel. The scheduling component 1210 may schedule, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE. The transmission component 1204 may transmit, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

The reception component 1202 may receive a communication from the second UE on one of the one or more scheduled sidelink resources. The reception component 1202 may receive a communication from the second UE on one of the one or more candidate sidelink resources that is not one of the one or more scheduled sidelink resources.

The number and arrangement of components shown in FIG. 12 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in FIG. 12. Furthermore, two or more components shown in FIG. 12 may be implemented within a single component, or a single component shown in FIG. 12 may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in FIG. 12 may perform one or more functions described as being performed by another set of components shown in FIG. 12.

FIG. 13 is a block diagram of an example apparatus 1300 for wireless communication. The apparatus 1300 may be a first UE, or a first UE may include the apparatus 1300. In some aspects, the apparatus 1300 includes a reception component 1302 and a transmission component 1304, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus 1300 may communicate with another apparatus 1306 (such as a UE, a base station, or another wireless communication device) using the reception component 1302 and the transmission component 1304. As further shown, the apparatus 1300 may include a selection component 1308, among other examples.

In some aspects, the apparatus 1300 may be configured to perform one or more operations described herein in connection with FIGS. 1-9. Additionally, or alternatively, the apparatus 1300 may be configured to perform one or more processes described herein, such as process 1100 of FIG. 11. In some aspects, the apparatus 1300 and/or one or more components shown in FIG. 13 may include one or more components of the UE described above in connection with FIG. 2. Additionally, or alternatively, one or more components shown in FIG. 13 may be implemented within one or more components described above in connection with FIG. 2. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component 1302 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 1306. The reception component 1302 may provide received communications to one or more other components of the apparatus 1300. In some aspects, the reception component 1302 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components of the apparatus 1300. In some aspects, the reception component 1302 may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with FIG. 2.

The transmission component 1304 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 1306. In some aspects, one or more other components of the apparatus 1300 may generate communications and may provide the generated communications to the transmission component 1304 for transmission to the apparatus 1306. In some aspects, the transmission component 1304 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus 1306. In some aspects, the transmission component 1304 may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with FIG. 2. In some aspects, the transmission component 1304 may be co-located with the reception component 1302 in a transceiver.

The reception component 1302 may receive, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources. The transmission component 1304 may transmit, to the second UE, a communication in one of the one or more candidate sidelink resources.

The reception component 1302 may sense the sidelink channel, and the transmission component 1304 may transmit the communication to the second UE in one of the one or more candidate sidelink resources that is not among the one or more scheduled sidelink resources, based at least in part on the sensing of the sidelink channel. The transmission component 1304 may transmit a request for the one or more candidate sidelink resources.

The selection component 1308 may select the one of the one or more candidate sidelink resources based at least in part on sidelink resource information from a third UE.

The number and arrangement of components shown in FIG. 13 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in FIG. 13. Furthermore, two or more components shown in FIG. 13 may be implemented within a single component, or a single component shown in FIG. 13 may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in FIG. 13 may perform one or more functions described as being performed by another set of components shown in FIG. 13.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

The following provides an overview of some Aspects of the present disclosure:

Aspect 1: A method of wireless communication performed by a first user equipment (UE), comprising: selecting one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE; scheduling, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE; and transmitting, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

Aspect 2: The method of Aspect 1, further comprising receiving a communication from the second UE on one of the one or more scheduled sidelink resources.

Aspect 3: The method of Aspect 2, wherein the communication is an initial transmission of a transport block from the second UE.

Aspect 4: The method of Aspect 1, further comprising receiving a communication from the second UE on one of the one or more candidate sidelink resources that is not one of the one or more scheduled sidelink resources.

Aspect 5: The method of any of Aspects 1-4, wherein the indication includes a bitmap for the one or more candidate sidelink resources, and wherein the one or more scheduled sidelink resources are marked in the indication.

Aspect 6: The method of any of Aspects 1-5, wherein the indication is transmitted according to a periodic pattern.

Aspect 7: The method of any of Aspects 1-6, wherein the indication is transmitted for a generated packet that has not been transmitted.

Aspect 8: The method of any of Aspects 1-7, wherein the indication is transmitted based at least in part on a request from the second UE or a triggering event.

Aspect 9: A method of wireless communication performed by a first user equipment (UE), comprising: receiving, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources; and transmitting, to the second UE, a communication in one of the one or more candidate sidelink resources.

Aspect 10: The method of Aspect 9, wherein transmitting the communication includes transmitting the communication to the second UE in one of the one or more scheduled sidelink resources.

Aspect 11: The method of Aspect 9 or 10, wherein the communication is an initial transmission of a transport block to the second UE.

Aspect 12: The method of any of Aspects 9-11, further comprising sensing the sidelink channel, and wherein transmitting the communication includes transmitting the communication to the second UE in one of the one or more candidate sidelink resources that is not among the one or more scheduled sidelink resources, based at least in part on the sensing of the sidelink channel.

Aspect 13: The method of any of Aspects 9-12, wherein the indication includes a bitmap for the one or more candidate sidelink resources, and wherein the one or more scheduled sidelink resources are marked in the indication as scheduled.

Aspect 14: The method of any of Aspects 9-13, wherein the communication is a generated packet that has not been transmitted.

Aspect 15: The method of any of Aspects 9-14, further comprising transmitting a request for the one or more candidate sidelink resources.

Aspect 16: The method of any of Aspects 9-15, further comprising selecting the one of the one or more candidate sidelink resources based at least in part on sidelink resource information from a third UE.

Aspect 17: The method of Aspect 16, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources indicated by the second UE, and wherein the method includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the third UE.

Aspect 18: The method of Aspect 16 or 17, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of a packet priority or a remaining packet delay budget.

Aspect 19: The method of any of Aspects 16-18, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of an application of a fairness rule to the second UE and the third UE or a buffer status corresponding to flows from the first UE to the second UE and the third UE.

Aspect 20: The method of any of Aspects 16-19, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of sidelink channel state information reports for the second UE and the third UE, pathloss information for the second UE and the third UE, distance estimations for the second UE and the third UE, or zone identifiers for the second UE and the third UE.

Aspect 21: The method of any of Aspects 16-20, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on, for links to the second UE and the third UE, one or more of reliability requirements, power control levels, feedback message utilization states, communication range requirements, or communication cast types.

Aspect 22: The method of any of Aspects 16-21, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method further comprises considering a conflicted scheduled sidelink resource as unavailable for transmission and transmitting the communication on another scheduled sidelink resource or candidate sidelink resource indicated by the second UE.

Aspect 23: The method of any of Aspects 16-22, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method further comprises considering a conflicted scheduled sidelink resource as available for transmission and proceeding with transmitting the communication on a conflicted candidate sidelink resource or a conflicted scheduled sidelink resource, based at least in part on one or more of: a location of the third UE with respect to one or more of the first UE or the second UE; a network layout of the third UE with respect to one or more of the first UE or the second UE; or a sensing result for the conflicted scheduled sidelink resource satisfying an interference threshold.

Aspect 24: The method of any of Aspects 9-23, wherein the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the method further comprises selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs per group of UEs.

Aspect 25: The method of any of Aspects 9-24, wherein the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the method further comprises selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs per geographical cluster of UEs.

Aspect 26: The method of any of Aspects 9-25, wherein the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the method further comprises postponing selection of the one of the one or more candidate sidelink resources for transmission.

Aspect 27: The method of any of Aspects 9-26, wherein the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the method further comprises selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs, without consideration of the one or more candidate sidelink resources indicated by the second UE.

Aspect 28: The method of Aspect 27, further comprising iteratively removing sidelink resource information for individual UEs of the other UEs from consideration until an availability threshold is satisfied.

Aspect 29: The method of any of Aspects 9-28, wherein the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with one of the one or more scheduled sidelink resources indicated by the second UE, and wherein the method further comprises selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs based at least in part on a specified parameter for the first UE satisfying a parameter threshold.

Aspect 30: The method of any of Aspects 9-29, wherein the sidelink resource information from one or more other UEs includes one or more scheduled sidelink resources that conflict with one of the one or more scheduled sidelink resources indicated by the second UE, and wherein the method further comprises selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by candidate sidelink resources in the sidelink resource information from the one or more other UEs.

Aspect 31: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 1-30.

Aspect 32: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the memory and the one or more processors configured to perform the method of one or more of Aspects 1-30.

Aspect 33: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 1-30.

Aspect 34: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 1-30.

Aspect 35: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 1-30.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, and/or a combination of hardware and software. “Software” shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, and/or functions, among other examples, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. As used herein, a processor is implemented in hardware, firmware, and/or a combination of hardware and software.

It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware, and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code—it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

As used herein, satisfying a threshold may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like.

Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. A used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items, and may be used interchangeably with “one or more.” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more.” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items), and may be used interchangeably with “one or more.” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has,” “have,” “having,” and/or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or,” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of”). 

What is claimed is:
 1. A first user equipment (UE) for wireless communication, comprising: a memory; and one or more processors, coupled to the memory, configured to: select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE; schedule, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE; and transmit, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.
 2. The first UE of claim 1, wherein the one or more processors are configured to receive a communication from the second UE on one of the one or more scheduled sidelink resources.
 3. The first UE of claim 2, wherein the communication is an initial transmission of a transport block from the second UE.
 4. The first UE of claim 1, wherein the one or more processors are configured to receive a communication from the second UE on one of the one or more candidate sidelink resources that is not one of the one or more scheduled sidelink resources.
 5. The first UE of claim 1, wherein the indication includes a bitmap for the one or more candidate sidelink resources, and wherein the one or more scheduled sidelink resources are marked in the indication.
 6. The first UE of claim 1, wherein the indication is transmitted according to a periodic pattern.
 7. The first UE of claim 1, wherein the indication is transmitted for a generated packet that has not been transmitted.
 8. The first UE of claim 1, wherein the indication is transmitted based at least in part on a request from the second UE or a triggering event.
 9. A first user equipment (UE) for wireless communication, comprising: a memory; and one or more processors, coupled to the memory, configured to: receive, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources; and transmit, to the second UE, a communication in one of the one or more candidate sidelink resources.
 10. The first UE of claim 9, wherein the one or more processors, to transmit the communication, are configured to transmit the communication to the second UE in one of the one or more scheduled sidelink resources.
 11. The first UE of claim 9, wherein the communication is an initial transmission of a transport block to the second UE.
 12. The first UE of claim 9, wherein the one or more processors are configured to sense the sidelink channel and transmit the communication to the second UE in one of the one or more candidate sidelink resources that is not among the one or more scheduled sidelink resources, based at least in part on the sensing of the sidelink channel.
 13. The first UE of claim 9, wherein the indication includes a bitmap for the one or more candidate sidelink resources, and wherein the one or more scheduled sidelink resources are marked in the indication as scheduled.
 14. The first UE of claim 9, wherein the communication is a generated packet that has not been transmitted.
 15. The first UE of claim 9, wherein the one or more processors are configured to transmit a request for the one or more candidate sidelink resources.
 16. The first UE of claim 9, wherein the one or more processors are configured to select the one of the one or more candidate sidelink resources based at least in part on sidelink resource information from a third UE.
 17. The first UE of claim 16, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources indicated by the second UE, and wherein the one or more processors are configured to select the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the third UE.
 18. The first UE of claim 16, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and the one or more processors are configured to select the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of a packet priority or a remaining packet delay budget.
 19. The first UE of claim 16, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the one or more processors are configured to select the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of an application of a fairness rule to the second UE and the third UE or a buffer status corresponding to flows from the first UE to the second UE and the third UE.
 20. The first UE of claim 16, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the one or more processors are configured to select the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of sidelink channel state information reports for the second UE and the third UE, pathloss information for the second UE and the third UE, distance estimations for the second UE and the third UE, or zone identifiers for the second UE and the third UE.
 21. The first UE of claim 16, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the one or more processors are configured to select the one of the one or more candidate sidelink resources for transmission based at least in part on, for links to the second UE and the third UE, one or more of reliability requirements, power control levels, feedback message utilization states, communication range requirements, or communication cast types.
 22. The first UE of claim 16, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the one or more processors are configured to consider a conflicted scheduled sidelink resource as unavailable for transmission and transmit the communication on another scheduled sidelink resource or candidate sidelink resource indicated by the second UE.
 23. The first UE of claim 16, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the one or more processors are configured to consider a conflicted candidate sidelink resource or a conflicted scheduled sidelink resource as available for transmission and proceed with transmitting the communication on the conflicted scheduled sidelink resource, based at least in part on one or more of: a location of the third UE with respect to one or more of the first UE or the second UE; a network layout of the third UE with respect to one or more of the first UE or the second UE; or a sensing result for the conflicted scheduled sidelink resource satisfying an interference threshold.
 24. The first UE of claim 16, wherein sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the one or more processors are configured to select the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs per group of UEs.
 25. The first UE of claim 16, wherein sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the one or more processors are configured to select the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs per geographical cluster of UEs.
 26. The first UE of claim 16, wherein sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the one or more processors are configured to postpone selection of the one of the one or more candidate sidelink resources for transmission.
 27. The first UE of claim 16, wherein sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the one or more processors are configured to select the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs, without consideration of the one or more candidate sidelink resources indicated by the second UE.
 28. The first UE of claim 27, further comprising iteratively removing sidelink resource information for individual UEs of the other UEs from consideration until an availability threshold is satisfied.
 29. The first UE of claim 16, wherein sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with one of the one or more scheduled sidelink resources indicated by the second UE, and wherein the one or more processors are configured to select the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs based at least in part on a specified parameter for the first UE satisfying a parameter threshold.
 30. The first UE of claim 16, wherein sidelink resource information from one or more other UEs includes one or more scheduled sidelink resources that conflict with one of the one or more scheduled sidelink resources indicated by the second UE, and wherein the one or more processors are configured to select the one of the one or more candidate sidelink resources for transmission that is also indicated as available by candidate sidelink resources in the sidelink resource information from the one or more other UEs. 